基于滑动模型的车辆里程仪标度因数标定方法

Calibration of odometer's scale factor based on sliding model

为提高车载导航系统中里程仪标度因数在非匀速条件下的标定精度,建立了车辆运动的动力学简化模型,分析了车辆加、减速时轮胎相对路面滑动对里程仪测量精度的影响,推导了基于路面附着系数的相对滑动模型,利用导航初始阶段惯导精度高的特点,将惯导解算位置作为基准,采用卡尔曼滤波器对里程仪标度因数进行估计。验证实验表明,经过改进的算法可以在车辆非匀速条件下对里程仪标度因数进行精确估计。相比未经滑动修正的估计值,里程仪测量精度由0.16%提高到0.02%。

For achieving the accurate calibration of an odometer＇s scale factor at uneven speed in vehicle navigation system,the simplified dynamic model of vehicle motion is built,the influence of relative sliding between tire and surface on the odometer＇s measurement precision is analyzed when acceleration and deceleration,and the relative sliding model based on road friction coefficient is derived.The outputs of strapdown inerial navigation system（SINS） have high precision at the initial phase of navigation,and the odometer＇s scale factor is calibrated using Kalman filter based on position output.The test result shows that high calibration precision can be achieved with vehicle variable velocity.The calibrated odometer is used for dead reckoning,the longitudinal measurement accuracy is improved from 0.16% to 0.02% compared with the uncorrected estimate.